Species Diversity, Growth, Status, and Biovolume of Taia River Riparian Forest in Southern Sierra Leone: Implications for Community-Based Conservation

Abstract

Riparian forest inventory is essential in understanding the floristic biodiversity and provides necessary information on the growth trend and status of plant diversity along forest ecosystem, especially the riparian forests. This study was undertaken to assess the species diversity, growth status, and bio-volume of Taia riparian forest for community-based conservation intervention. In this study, we enumerated 602 individual trees, which comprised 49 species that belong to 37 genera in 25 families. In total, 14 rectangular plots of dimension 20 × 50 m2 were demarcated. All trees species within the sampled plots having diameter at breast height [Dbh] ≥7 cm were identified and height measured using the Haga altimeter, girth and measuring tape to determine the growth status. The result shows that 83% of the trees enumerated have [Dbh] that range from 7 to 30 cm, whereas 17% had [Dbh] greater than 30 cm. Funtumia africana and Trichilia heudelotii were the dominant species in almost all aspects in the study area. Meliaceae, Apocynaceae, and Mimosaceae were the dominant families with the highest species. The Shannon diversity index was 3.094, whereas the Simpson and Evenness diversity was 0.9303 and 0.4502, respectively. Other diversity indices estimated were Margalef 7.544, Equitability 0.7949, and Fisher_alpha 12.77. The overall biovolume was 283.05 m,3 with a total basal cover of 12.54 m2. Height and [Dbh] were not significantly correlated with the biovolume. Biotic pressure such as fuelwood collection, unsustainable charcoal production, pole harvesting, bushfires, and other traditional and cultural functions contributes greatly to the exploitation of the riparian forest. Therefore, urgent strategic conservation and protection measures should be adopted to prevent further degradation of forest ecosystems along river banks in the district and other ecologies in Sierra Leone.